Question: Rewrite ${\dfrac{7^{-4}}{7^{-7}}}$ in the form ${7^n}$.
Solution: ${ \dfrac{7^{-4}}{7^{-7}} = 7^{-4-(-7)}} $ ${ \hphantom{\dfrac{7^{-4}}{7^{-7}}} = 7^{3}} $